The acute lung injury (also known as ALI) and acute respiratory distress syndrome (also known as ARDS and representing the more severe expression of ALI) are associated with diffuse cellular infiltration and proteinacious edema (Ware L B. The ARSD. NEJM 2000; 34: 660-1). This fact is a reflection of a significant lung inflammatory state, with activation of humoral and cellular mediators causing changes in lung architecture itself, which induce serious disturbances in pulmonary gas exchange. ALI/ARDS may be due from both intra-pulmonary (bacterial or viral pneumonia, aspiration, inhalation of gases, graft dysfunction in lung transplant, cystic fibrosis, . . . ) and extra-pulmonary processes (sepsis, pancreatitis, polytransfusion, etc), but the more frequent cause is bacterial pneumonia.
Substantial progress has been made in reducing mortality and morbidity from ALI and the ARDS with improved supportive care, specifically lung-protective ventilation and a fluid-conservative strategy. However, morbidity and mortality remains unacceptably high. In fact, ALI is responsible for up to 75,000 deaths and 3.6 million hospital days in the United States each year (Rubenfeld G O. Incidence and outcome of ALI. NEJM 2005; 353: 1685-93). These data demonstrate that it has a substantial impact on public health. Furthermore, pharmacologic therapies have not been successful in improving outcomes.
Another lung disease involved in the present invention is Chronic Obstructive Pulmonary Disease (COPD), which is defined according to the Global Initiative for Chronic
Obstructive Lung Disease (GOLD) as a persistent airflow limitation, which is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gases (Rabe K F et al. GOLD executive summary. Am J Respir Crit Care Med 2007; 176:532-555). The pathogenesis of COPD is characterized by an up-regulation of inflammatory processes leading to irreversible events such as apoptosis of epithelial cells, and proteolysis of the terminal air-space and lung extracellular matrix components. Interestingly, it has some significant extra-pulmonary effects that may contribute to the severity in individual patients. The reality, though, is that COPD is a heterogeneous group of diseases with similar manifestation and includes disparate and overlapping disease processes such as chronic bronchitis, emphysema, asthma, bronchiectasis, and bronchiolitis. The primary cause of COPD is tobacco smoke (including second-hand or passive exposure). However, other risk factors include air pollution, occupational dusts and chemicals, and it could present as a sequelae of lower respiratory infections.
COPD is a leading cause of disability and death. It is a chronic disease that continues to increase in prevalence and mortality, and it is projected to continue to increase into the future (Lopez A D et al. Chronic obstructive pulmonary disease: current burden and future projections. Eur Respir J 2006; 27:397-412). In fact, 80 million people have moderate to severe COPD and more than 3 million people died of COPD in 2005, which corresponds to 5% of all deaths globally (www.who.int). According to new estimates for 2030 by the World Health Organization, COPD is predicted to become the third leading cause of death (www.who.int). Moreover, the burden of COPD is rising, incurring a major health care burden worldwide.
The treatment objectives for COPD include slowing the accelerated decline in lung function; relieving symptoms, such as shortness of breath and cough; improving daily lung function; decreasing exacerbations; and improving quality of life (Pauwels R A, Buist A S, Calverley P M A, Jenkins C R, Hurd S S, on behalf of the GOLD Scientific Committee. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease. NHLBI/WHO Global Initiative for Chronic Obstructive Lung Disease (GOLD) workshop summary. Am J Respir Crit Care Med. 2001; 163:1256-1276). While many medications are available to treat COPD, such as bronchodilators and steroids, no drug has demonstrated effectiveness in halting the progression of the disease. Rather, the available pharmacological treatments are essentially symptomatic and the goal of drug therapy at this time is to maintain control of symptoms and to prevent COPD exacerbation. In fact, there is no specific therapy other than smoking cessation in case of smoking-induced emphysema, which is only partially successful in established disease.
Still another lung disease involved in the present invention is asthma. By definition, asthma is a heterogeneous chronic inflammatory disorder of the airways involving an airflow limitation that is at least partly reversible. The condition results in recurrent episodes of wheezing, breathlessness, chest tightness, and cough (Global Initiative for Asthma (GINA)). Global strategy for asthma management and prevention. NIH publication number 95-3659a. Bethesda, National Institutes of Health, 1995). Asthma definition includes four domains: variable airway obstruction, airway inflammation, airway hyperresponsiveness, and symptoms, which characterize the underlying disease process.
Perhaps one the most important advances in the treatment of asthma occurred when the inflammatory component of the condition was demonstrated and found to be satisfactorily treated with inhaled corticoids. Early pathological studies in patients with mild asthma who were not treated with corticosteroids reported high eosinophil and lymphocyte counts in the mucosa of the large airways. The number of these cells decreased significantly and the overall lung function improved following administration of high doses of inhaled corticosteroids (Djucanovic R, Wilson J W, Britten K M, Wilson S J, Walls A F, Roche W R, Howarth P H, Holgate S T. Effect of an inhaled corticosteroid on airways inflammation and symptoms in asthma. Am Rev respir Dis 1992; 256:669-674; Laitinen L A, Laitinen A, Haahtela T. A comparative study of the effects of an inhaled corticosteroid, budesonide, and a beta 2-agonist, terbutaline, on airways inflammation in newly diagnosed asthma: a randomized, double blind, parallel-group controlled trial. J Allergy Clin Immunol 1992; 90:32-42).
Other medications are available to treat asthma, such as bronchodilators. All these treatments are able to reduce inflammation although not totally. Moreover, in some patients, hiperresponsiveness is still present despite the fact that inflammation is reduced, demonstrating that no drug has proven effective to cure the disease.
Still another lung disease involved in the present invention is hypersensitivity pneumonitis. This is a clinical entity characterized by a disintegration of the lung parenchyma and progressive development of pulmonary fibrosis as a result of an immunologic inflammatory response to various antigens after a previous sensitization (Selman M. Hypersensitivity Pneumonitis: a multifaceted deceiving disorder. Clin Chest Med. 2004; 25: 531-547). The progression of the disease leads to chronic respiratory failure due to the development of pulmonary fibrosis established or, in some cases, to chronic obstructive pulmonary disease (COPD), which confers a status of potential severity of this entity (Hanak V, Golbin J M, Ryu J H. Causes and presenting features in 85 consecutive patients with hypersensitivity pneumonitis. Mayo Clin Proc. 2007; 82: 812-816. Selman M, Chapela R, Raghu G. Hypersensitivity pneumonitis: clinical, manifestations, pathogenesis, diagnosis, and therapeutic strategies. Semin Respir Med. 1993; 14: 353-364). In fact, pulmonary fibrosis proved to be a predictor of mortality in these patients, with a mortality of 27% at 5 years and a median survival of 12.8 years (Vourlekis J S, Schwarz M I, Cherniack R M, Curran-Everett D, Cool C D, Tuder R M, King T E, Brown K K. The effect of pulmonary fibrosis on survival in patients with hypersensitivity pneumonitis. Am J Med 2004; 116(10): 662-8.). After inhalation of the antigen, mononuclear infiltrates with a peribronquiovascular distribution are developed (Denis, M., Y. Cormier, and M. Laviolette. 1992. Murine hypersensitivity pneumonitis: a study of cellular infiltrates and cytokine production and its modulation by cyclosporin A. Am. J. Respir. Cell Mol. Biol. 6: 68-74. Denis, M., Y. Cormier, M. Laviolette, and E. Ghadirian. 1992. T cells in hypersensitivity pneumonitis: effects of in vivo depletion of T cells in a mouse model. Am. J. Respir. Cell Mol. Biol. 6: 183-189). These mononuclear infiltrates are composed predominantly of alveolar macrophages and T cells. Th2 cytokines enhance fibrotic processes by activating fibroblast proliferation and collagen production (Mitaka K, Miyazaki Y, Yasui M, Furuie M, Miyake S, Inase N, Yoshizawa Y. Th2-biased Immune responses are important in a murine model of chronic hypersentivity pneumonitis. Int Arch Allergy Immunol 2011; 154: 264-74). Some authors have described TH2-type immune responses in the lesions of usual interstitial pneumonia in patients with hypersensitivity pneumonitis, as has been described in idiopathic pulmonary fibrosis (Kishi M, Miyazaki Y, Jinta T, Furusawa H, Ohtani Y, Inase N, Yoshizawa Y. Pathogenesis of cBFL in common IPF Correlation of IP-10/TARC ratio with histological patterns. Thorax 2008; 63: 810-6) which is a serious entity with a life expectancy of 3.2 to 5 years from diagnosis (Idiopathic Pulmonary Fibrosis: Diagnosis and treatment. International Consensus Statement. Am J Respir Crit Care Med. 2000; 161.646-64; Fernandez Perez E R, Daniels C E, Schroeder D R, St Sauver J, Hartman T E, Bartholmai B J, Yi E S, Ryu J H. Incidence, prevalence, and clinical course of idiophatic pulmonary fibrosis: a population-based study. Chest 2010; 137(1):129-37).
Thus, in view of the above, there is a need for developing new and more effective therapies for the treatment of airway immune inflammatory and lung diseases. The present inventors have surprisingly found that engineered human mesenchymal stem cells overexpressing the IL-33 decoy receptor sST2 are able to attenuate acute and chronic airway immune inflammatory and lung diseases.
IL-33 is suggested to function as an alarmin that is released upon endothelial and epithelial cell damage. It has recently shown that IL-33 plays a crucial role in innate airway inflammation, but its mechanism of action is still unclear. Indeed, no consensus has been reached whether IL-33 is pro-inflammatory (Oboki et al. (2011) Allergy Asthma Immunol. Res. 3: 81-88) or exerts a protective role in inflammatory states (Miller et al. (2010) Circ. Res. 107: 650-8; Alves-Filho et al. (2010) Nat. Med. 16: 708-12). On the other hand, individuals who did not recover from sepsis, a generalized bacterial infection resulting in widespread inflammation and multiple organ failure, had significantly more sST2 than those who did recover. The present inventors prove herein that the combination of the local and continuous action of both the intrinsic immunomodulatory and anti-inflammatory properties of hMSCs (human mesenchymal stem cells) and the transgenic over-expression of the anti-inflammatory decoy receptor sST2, are able to act synergistically and alleviate the pathological events of acute and chronic airway immune-inflammatory and lung diseases.
The present inventors have demonstrated or shown:
That ASCs (adult stem cells) have lung tropism (good in terms of general safety and therapeutic efficacy to airway and lung diseases).
Selective and persistent (local) sST2 delivery by using ASCs as a continuous sST2 factory (through continuous sST2 over-expression and secretion into the local lung environment).
Synergistic benefits on acute lung injury (ALI), combining the intrinsic immunoregulatory properties of ASCs with the anti-inflammatory action of sST2 as decoy receptor for IL-33.
A profound local anti-inflammatory effect of our cell therapy strategy, reaching both regulatory actions over the cell-mediated, acquired immune response (immunoregulatory action of ASCs, which we demonstrate that are able to induce, among others, anti-inflammatory factors such as COX-2, IDO and TGF-beta). This action is combined with the over-expression of sST2 in these cells by genetic engineering, which acts as decoy receptor for IL-33. This cytokine has been shown to be a crucial amplifier of innate immunity (Oboki et al. (2010) Proc. Natl. Acad. Sci. USA 107: 18581-6). Thus, with our approach, we control both the adaptive and the innate immunity, something which has not been disclosed nor suggested so far. The complete immune response is responsible for the initiation and development of the full inflammatory process occurring in ALI and other lung related pathologies, and the main contributor of airway injury.
Mesenchymal stem cells (MSCs) are multipotent adult stem cells that can be isolated from several sources (bone marrow, cord blood, placenta and adipose tissue) and have the capacity to differentiate into a wide number of cells. MSCs release several growth factors that can regulate endothelial and epithelial permeability, as well as enhance repair. MSCs also release anti-inflammatory cytokines that can dampen the severity of inflammation. Furthermore, MSCs can regulate innate and adaptive immunity by effects on T and B cells, dendritic cells, monocytes, neutrophils, and macrophages.
Based on preclinical studies, MSCs reduce the severity of organ injury as well as enhance recovery (Matthay M A et al. Chest 2010; 138: 965-972). Several experimental studies have shown that MSCs may have potential therapeutic application in clinical disorders, including myocardial infarction, diabetes, hepatic failure, acute renal failure, and sepsis.
On the other hand, a recent review (Smith D E. IL-33: a tissue derived cytokine pathway involved in allergic inflammation and asthma. Clin Exp Allergy. 2010 February; 40(2):200-8) shows that IL33 is one of the main cytokines that contribute to inflammation in asthma and allergy. In addition, experimental evidence and clinical observations have associated ST2 with immune-inflammatory processes such as asthma (Sweet M J, et al. A novel pathway regulating lipopolysaccharide-induced shock by ST2/T1 via inhibition of Toll-like receptor 4 expression. J Immunol. 2001; 166(11):6633-9). Moreover, using different models of lung inflammation, it has been postulated a role of sST2 in the attenuation of immune responses mediated by Th2 cells (Hayakawa H, et al. Soluble ST2 blocks interleukin-33 signaling in allergic airway inflammation. J Biol Chem. 2007 Sep. 7; 282(36):26369-80). sST2 acts as a negative regulator of the production of Th2 cytokines (IL-4, IL-5, IL-13), triggering the inflammatory response in asthma, by antagonizing signaling via IL-33 and suppressing the activation of NF-kappaB.
In view of the above, the object of the present invention is to provide a new therapy based on engineered mesenchymal stem cells for use in the treatment of airway immune inflammatory and lung diseases.
A second object of the present invention is to provide a pharmaceutical composition based on mesenchymal stem cells for use in the treatment of airway immune inflammatory and lung diseases.